How to Troubleshoot a Toro Lawnmower GTS-5

Refill the gas tank if there is no fuel present. If the tank has gasoline and you have not used the mower in more than 30 days, it is possible that the fuel has degraded and won't power the mower effectively. In this case you must use a drainage pump and remove the gasoline then refill it with clean unleaded gas. The operating instructions for each kind of drainage pump are different. However, it will typically involve uncapping the gas tank located near the top of the mower and placing a hose into the gas tank. The pump will siphon the gasoline out of the tank. Fill the lawnmower with new gas and wipe the exterior of the lawnmower clean of any excess fuel that may have leaked out. Restart the engine.

Remove the dipstick from the engine to change the oil. The oil capacity is only 20 ounces and shouldn't be very messy to change. Place an oil pan on the ground and tip the mower on its side to drain the oil into the pan. Re-fill the engine with 10W-30 engine oil and be sure to not fill it past the dipstick marker. Securely place the dipstick back into its tube.

Remove the spark plug wires located on each side of the lawnmower. Pull the wire from the socket to expose the spark plug, enabling you to remove it by hand. Inspect the plug for wetness, foul smelling odor or a burnt appearance; these are signs of a failing spark plug and could prevent the engine from starting. Replace the plugs with Champion brand RJ119LM spark plugs gapped at .030 inches. This is the type that the mower originally came with from the manufacturer. Other brands can be used as well, but they must all be gapped properly.